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  • Author or Editor: Z. Horváth x
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Authors: A. Dávid, G. Horváth, Z. Mészáros, T. Meisel and Z. Halmos
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Abstract

The identification of property changes and damage in various structures is one of the major points in the engineering society. This work contains the method and results of a long-term aging process implemented by an experimental system. We applied a chemical and heat artificial aging test on metal and plastic pipes to indicate the degradation levels and results with suitable measuring instruments. During our measurements of aged pipes vibration tests were performed to get information about the changing of the vibration spreading properties of different materials. We were searching for information about the property changing of widely used pipe materials to estimate the rate of degradation and the service life of these instruments more accurately.

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Authors: B. Kovács, J. Horváth, O. Pálmai, T. Németh and Z. Győri

Agricultural goods obtained and produced in Hungary have played an important role in the markets of Western Europe. By utilizing the ecological potentials of the Carpathian Basin, local inhabitants are in the position to produce considerable food surpluses in addition to meeting their own demands. With agricultural production becoming more and more intensive in Hungary, the application of mineral fertilizers also started to increase slowly from the 1960’s. From the mid-1970’s a uniform sampling, soil testing and fertilization extension system was created together with its own institutional and laboratory testing network. The intensive use of mineral fertilizers in Hungary lasted from the mid-1970’s to the last quarter of the 1980’s, during which an average amount of 230 kg·ha -1 NPK fertilizer was applied. In this period the so-called “build-up” fertilization was applied in conformity with the improvement of all other elements involved in the production technology, which was also clearly expressed in the agro-political objectives of those days aiming to obtain higher yields. At that time the nutrient supply and nutrient base of soils in Hungary increased clearly, so the production technology could no longer limit higher yields. In 1990 agriculture changed fundamentally and radically in Hungary, and the same was valid for nutrient supplies as well. At the beginning of the 1990’s there was a sudden decrease in the level of mineral fertilizer application (to below 40 kg NPK active ingredients·ha -1 ), followed by a slow increase, which has reached the level of almost 70 kg·ha -1 by today. In the meantime the animal stock in Hungary has decreased and consequently the amount of manure has also fallen. All in all, the nutrient balance of Hungarian soils has always been negative since 1989. Due to the changes in its structure and ownership over the past twenty years or so, it has become very difficult to obtain reliable information about Hungarian agriculture. The Soil Resources Management General Partnership (in Hungarian: Talajerőgazdálkodás Kkt.) conducts extension work based on soil sampling and has a continuous flow of data on over thirty thousand hectares, beginning at the end of the 1970’s. Based on the analyses of these data it can be stated that the extra amount of nutrients over balance, applied during the period of replenishment (until the change in regimes) has been „removed” from the soil over the past fifteen years, consequently the Hungarian nutrient balance has become negative again. This kind of fertilization practice cannot be sustained in Hungary, as the maintenance of the production potential of Hungarian soils is far from being resolved at the moment; it poses risks to and questions sustainability, as well as it may cause a very serious competitive disadvantage to the country.

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The coat protein (CP) gene from a necrotic strain of potato virus Y (PVY) has been engineered into two-old Hungarian cultivars, namely cv. Mindenes and Somogyi kifli. The integration of the coat protein gene was confirmed by polymerase chain reaction (PCR) using genomic DNA preparations. The transcription and the expression of the integrated CP gene was followed by Northern and Western blot. The pathogene derived resistance was demonstrated by mechanical inoculation of the trans­formant plants after the transfer of the regenerants into soil. The efficiency of the virus protection varied between different potatoes ranging to complete protection to no protection. All plants were tested in field conditions under the special licence, given the competent authority instructed by the Hungarian gene technology act. In two consecutive years three Mindenes independent transformants proved to be highly resistant against two different strains of PVY in provocative experiment.

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Authors: B. Czúcz, Zs. Molnár, F. Horváth and Z. Botta-Dukát

In this paper we present an implementation of the natural capital index (NCI), a highly aggregated policy-relevant biodiversity indicator for Hungary, based on the MÉTA database, a detailed field-based vegetation database with a habitat quality attribute. To this end, we introduce two different weighting schemes for the field-estimated MÉTA values, both rooted in the concept of ecosystem services: a linear “equal steps” (NCI lin ) and an exponential (NCI exp ) weighting scheme. The natural capital index of Hungary and its physical geographical regions are calculated and presented from both aspects. The national NCI lin is 9.9% (indicating an overall 90% loss in the availability of the major supporting ecosystem services), and NCI exp is 3.2% (indicating an even greater degree of loss in terms of the conservation of rare species). The geographical regions of Hungary exhibit considerable spatial variation, which reveals important information on their basic characteristics (e.g. agricultural potential) and land use history. As NCI can be calculated on any spatial scales from local to national, this indicator may become a useful tool for policy development and evaluation purposes, including environmental impact assessments (EIA) and strategic environmental assessments (SEI). However, due to several conceptual limitations (e.g. disregard for rarity, spatial structure and cultural values, questions of recency and repetition) NCI should not be regarded as a self-sufficient universal tool, and strategic decisions should be based on careful consideration of all potentially relevant factors.

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The performance of the VITEK 2 System (bioMérieux) version 3.01 software was compared to that of the E-test (AB Biodisk, Solna, Sweden) for antibiotic susceptibility testing of 17 clinical isolates of vancomycin resistant enterococcus (VRE). Antibiotic Susceptibility Testing (AST) by VITEK 2 produced 10 minor (59%) errors, resulting in false phenotypes. Reporting of vancomycin resistance in enterococcal strains has enormous therapeutic and epidemiological consequences. Therefore, at laboratories using automated systems (e.g. VITEK 2) for routine microbiological susceptibility testing data must be confirmed by independent validated methods, e.g. E-test, or microdilution.

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Experiments were carried out on sperm cryopreservation of two European percid fish species, the pikeperch (Sander lucioperca) and the Volga pikeperch (S. volgensis) . Two experiments were conducted on pikeperch sperm. In the first, the effects of three extenders (Glucose, KCl, Sucrose) and two cryoprotectants (dimethyl-sulfoxide: DMSO, methanol: MeOH) were tested on motility and fertilization. In the second, the effects of two dilution ratios (1: 1, 1: 9) and two cryoprotectants (DMSO, MeOH) on hatching were investigated. In the experiment on Volga pikeperch the suitability of using cryopreservation for fertilization was investigated. In the first experiment on pikeperch the highest post-thaw motility (28 ± 21%) and fertilization rate (43 ± 12%) was found with DMSO as cryoprotectant in combination with Glucose extender. In the second, the highest hatch rate (41 ± 22%) was observed with MeOH as cryoprotectant and 1: 1 sperm dilution ratio, however no significant difference was found among the results. In the experiment on Volga pikeperch hatch rates with cryopreserved sperm (60 ± 2%) did not significantly differ from the control (60 ± 6%). Contamination of sperm with urine seems to be a key problem in the success of sperm cryopreservation of these species.

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Authors: Zs. Baji, Z. Lábadi, Z. E. Horváth, M. Fried, B. Szentpáli and I. Bársony

Abstract

This study on ALD grown ZnO layers is aimed at the systematic study of the effect of incorporation of different Al contents on the properties of the layers. An alternate precursor pulse method was used for layer deposition. Optimal doping was achieved at 210 °C at 2 at% Al content. A relationship between crystalline morphology versus temperature and aluminium incorporation was established.

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Authors: I. Boros, G. Horváth, S. Lehel, T. Márián, Z. Kovács, J. Szentmiklósi, G. Tóth and L. Trón

Abstract  

[11C]-labeled form of ten A2a adenosine receptor specific 8-styryl-7-methyl-xanthine derivatives ([11C]-caffeines) were synthesised by N-methylation of the corresponding 8-styryl-xanthine derivatives using [11C]-methyl iodide in optimized reaction conditions. The results show that the [11C]-methylations take place with excellent radiochemical yields (35–93%), and can be utilised easily in online preparations. These labeled ligands may facilitate the positron emission tomographic (PET) investigation of adenosine A2a receptors.

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Authors: G. Horvath, G. Joo, G. Kekesi, I. Farkas, G. Tuboly, Z. Petrovszki and G. Benedek

The goal was to develop a rat model for determination of the effects of intrathecally administered drugs on the peripherally induced pruritic behaviors. After chronic intrathecal catheterization, a serotonin derivative (5-methoxytryptamine: MeOT, 200 μg on both sides) was injected into the lower leg skin. After the first period (phase 0: 0–30 min) MeOT injection was repeated and opioid antagonist naltrexone (10 μg), NMDA receptor antagonists ketamine (10–100 μg), kynurenic acid (1–10 μg) or their combinations were injected intrathecally. The second observational period lasted for 60 min (phases I and II, 30–60 and 60–90 min, respectively). MeOT produced pruritic behavior with high degree of interindividual differences. The second MeOT injection caused an enhanced pruritic behavior in Phase I. Naltrexone decreased the pruritic activity, while neither doses of ketamine influenced the effects of MeOT. The higher doses of kynurenic acid resulted in notable decreases in the pruritic behavior. The combinations of naltrexone with ketamine or kynurenic acid produced a prolonged antipruritic effect. Our data suggest an important direction for the development of a new itch model in rats that focuses on the spinal mechanism of itching. Besides, the results revealed the role of the spinal opioid and NMDA receptors in this process.

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